If your hauling livestock I'd recommend tall stacks to keep the fumes away from the critters, otherwise tall stacks just end up with more tree/overhang damage.

 

I do not know you, so I don't know how much bedspace you need, but I would go with atleast 1 8" stack. Also I would get rid of the headache rack. If I were you and I had to have the headache rack, I would get a CM Hauler rack like this: TM Model Truck Beds - Trailer Country Truck Beds - TM Truck Bed Models If i were you, I would also get the kind the point out so, if your driving in the rain, you don't have to worry about getting water in your exhaust system. Plus, straight pipe those stacks! Straight piped powerstrokes sound great!! But, it is your truck. This is only my opinion. I heard of a guy that went to a local semi junkyard, and he got a nice set of chrome stacks off of a wrecked truck for $80.

 

ITS in denver had a over stock on stacks and i got 2- 6", 5' tall, chrome bull haulers for 40 bucks each.